Good questions Orly:
"so PEC requires an indexer?"
"also if the indexer is present, does the controller seek the indexer?"
PEC uses a "soft" index and an index offset. If index support is enabled, that index offset will be noted when the index arrives during playback and recording. The new index offset will take effect after the current sequence is complete.
Recording waits for the "soft" index, playback always starts immediately.
I'll be revisiting PEC and index support and will be making improvements in the future. One obvious improvement would be to allow Index detection during gotos, this should get the critical first detection done before any recording/playback happens. I specifically attached the hall-sensor signal to an external interrupt enabled pin of the MCU for this reason. The other improvement would be to allow recording to start immediately, this is a bit tricky and I had that working at one point but then changes broke it so I disabled the feature rather than trying to tackle that and add index support all at once.
PEC looks simple on the surface, but I've found it tricky to implement and very time consuming to test.
OnStep has been steadily improving and especially over the last year or so has started to reach a fairly refined state, but it's still in Beta and there are bugs and shortcomings. Some things are easily fixed/added with confidence and they immediately make there way to the Dev branch on GitHub. Others are of a more subtle nature and require testing under the stars to confirm that more good than harm is being done. The current experimental version allows goto rate setting in the ASCOM setup dialog, changes rate generation to fixed point math, lowers jitter during sidereal tracking, adds initial support for fork mounts, etc.
Of these the rate generation fix is the most important, I never noticed this on my mounts, but testing a wide range of configurations showed the problem. The fix is a much better all around way to do the same thing, and the same tests say it's all working perfectly, but I need to do some testing under the stars to make sure the rate generation is exact.
As always, I welcome feedback (bugs/improvements/features) and try to fix problems quickly once identified so stay in touch via my email (available on my site) or post here.
Edited by hjd1964, 04 March 2015 - 02:03 PM.